Preheat oven to 350 degrees F. Line two baking sheets with parchment paper, set to the side.

In a medium bowl, combine all the ingredients for the crumb topping. Using your hands or a fork (or pastry blender) rub the butter into the dry ingredients until it resembles coarse crumbs. Set aside.

In a large bowl combine the flour, baking powder, salt and cinnamon (for the cookie dough). In a separate bowl, cream together the butter, brown and granulated sugars, until light and fluffy. Add the eggs, one at at time, mixing well after each addition. Stir in the vanilla extract. Add the dry ingredients in batches, and stir until the dough comes together.

Using a medium ice cream scoop, portion out large rounds of cookie dough onto the prepared baking sheets, make sure to leave enough space in between. Make an indentation in the center of each cookie and sprinkle a rounded spoonful of the crumb topping. Bake for about 10 to 12 minutes or until golden brown around the edges. Remove from oven and allow to cool slightly on baking sheets. Transfer to wire racks and allow to cool down completely.

Dust cooled cookies with powdered sugar, and enjoy!